FYI: Trend CSM 3.5, Small Business Server 2003 and the .notaccount user account
I installed Trend CSM 3.5 on my SBS2003 server at the office a little while ago. A few days later I noted security alerts in my Server Performance Reports that merited further investigation.
The errors are the classic "unknown user name or bad password" which is not unusual in and of itself - all of us who look after servers see such errors quite regularly when the bad guys try to guess usernames and passwords in an attempt to get into our servers. What is unusual is that the username is strange, and the errors are occurring every day.
A little investigation reveals that the errors are being caused by Trend CSM 3.5. Messy Trend, very messy - I don't like my security logs being filled with aberrant 529 alerts.
I conducted a quick search of Trend's online knowledgebase for ".notaccount", and "error 529" and "529" with zero results, so I don't have a fix yet 
Screenshot of error:
